Purified air and methods of making and using the same

ABSTRACT

Purified air is provided, having a TVOC content of from less than 5 ppb to about 500 ppb, a Biologicals content of from less than 1 CFU/M 3  to 150 CFU/M 3  and a Particulate content of from about 1,000 0.3 μm particles per ft 3  to about 50,000 0.3 μm particles per ft 3 , or from about 600 0.5 μm particles per ft 3  to about 500,000 0.5 μm particles per ft 3 .

This is a divisional application of U. S. patent application Ser. No.13/554,366 which is a continuation-in-part of U.S. patent applicationSer. No. 13/244,973, filed on Sep. 26, 2011, which is a continuation ofU.S. patent application Ser. No. 12/732,246, filed on Mar. 26, 2010.International Application No. PCT/US2011/029567, filed on Mar. 23, 2011,claims priority to U.S. patent application Ser. No. 12/732,246.

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention relates to devices and methods for the filtration andpurification of air. More particularly, this invention relates to airpurifiers capable of providing a level of air quality suitable forenvironments that are highly sensitive to airborne contaminants, e.g.,in vitro fertilization laboratories or other medical environments.Further, the invention may be adapted for use in any substantiallyenclosed environment, including, but not limited to, homes, residentialbuildings, commercial buildings, hotels, cars, buses, trains, airplanes,cruise ships, educational facilities, offices, and government buildings.The invention may also have applications in, e.g., national security,defense, or airline industries.

2. Description of Related Art

In vitro fertilization (“IVF”) is a procedure whereby egg cells arefertilized by sperm in a laboratory environment, instead of in the womb.If an egg cell is successfully fertilized, it may be transferred intothe uterus of a patient wishing to become pregnant.

IVF may be an effective option for patients suffering from infertility,especially where other methods of assisted reproduction have failed.However, IVF is very expensive and is not typically covered by medicalinsurance. In 2009, the cost of a single cycle of IVF was approximately$10,000 to $15,000 in the United States. It is financially prohibitivefor most people to undergo multiple rounds of IVF. It is thereforeimperative that conditions for successful pre-implantation embryogenesisare optimized, in order to maximize the likelihood of success.

One extremely important factor contributing to the likelihood ofsuccessful pre-implantation embryogenesis is the air quality of the IVFlaboratory. Gametes and embryos grown in vitro are highly sensitive toenvironmental influences. Human embryos have no means of protection orfiltration against environmental toxins and pathogens. They arecompletely at the mercy of their environment. The incubators which housethe human embryos often consist of a significant percentage of room air.Although airborne contaminants can adversely affect embryogenesis,surprisingly little emphasis has been placed on optimizing laboratoryair quality during the last three decades in which IVF has beenavailable as a treatment for infertility.

Existing filtration devices have been found insufficient to optimize airquality to truly acceptable levels for IVF. For example, it has beenfound that laboratory air that had been filtered with only highefficiency particulate air (“HEPA”) filters was actually of lesserquality than outside air. Additionally, some filters produce by-productsor other contaminants that actually detract from the quality of the airin an IVF laboratory. For example, carbon filters can create carbondusting that is harmful to the IVF process. This is not to say, however,that carbon filters or HEPA filters should not be used to treat airsupplied to an IVF laboratory. On the contrary, it is preferred thatcarbon filters, HEPA filters, or their respective equivalents, areincluded among filtration media used to treat air supplied to an IVFlaboratory. Attaining optimal air quality in an IVF laboratory or othersubstantially enclosed space requires proper selection, combination andsequencing of various filtration media.

BRIEF SUMMARY OF THE INVENTION

Accordingly, air characterized by very high purity and methods of makingand using such air, are provided.

In one aspect of the present invention, air is provided, characterizedby a TVOC content of from less than 5 ppb to about 500 ppb, aBiologicals content of from less than 1 CFU/M³ to 150 CFU/M³ and aParticulate content of from about 1,000 0.3 μm particles per ft³ toabout 50,000 0.3 μm particles per ft³, or from about 600 0.5 μmparticles per ft³ to about 500,000 0.5 μm particles per ft³.

Another aspect of the present invention is a method of achieving an IVFclinical pregnancy rate of at least 50%. The method includes performingmultiple IVF cycles in an IVF laboratory having air characterized by aTVOC content of from less than 5 ppb to about 500 ppb, a Biologicalscontent of from less than 1 CFU/M³ to 150 CFU/M³ and a Particulatecontent of from about 1,000 0.3 μm particles per ft³ to about 50,000 0.3μm particles per ft³, or from about 600 0.5 μm particles per ft³ toabout 500,000 0.5 μm particles per ft³.

Another aspect of the present invention is a method of purifying air,including providing an air flow path through a housing for the flow ofair in a downstream direction, filtering the air through oxidizing andadsorbing VOC pre-filtration within the housing, filtering the airthrough UV filtration within the housing, downstream from the oxidizingand adsorbing VOC pre-filtration and filtering the air through finalparticulate filtration within the housing, downstream from the UVfiltration.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

The invention will be described in conjunction with the followingdrawings in which like reference numerals designate like elements andwherein:

FIG. 1 is a top view of an air purifier according to the presentinvention.

FIG. 2 is a side view of an air purifier according to the presentinvention.

FIG. 3 is an internal view of the air purifier along the plane definedby section line A-A of FIG. 1.

FIG. 4 is an internal view of the air purifier along the plane definedby section line B-B of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

Referring now in detail to the various figures of the drawings whereinlike reference numerals refer to like parts, there are shown in FIGS. 1and 2 top and side views, respectively, of an air purifier 2 accordingto the present invention. As illustrated, the air purifier 2 includes asubstantially rectangular cuboid housing 4 having an inlet 6 forreceiving air and an outlet 8 for exhausting air. The term “air” as usedherein broadly refers to a gas or gaseous mixture that may be safelybreathed by mammals and/or that can serve as a source gas or gaseousmixture towards an IVF laboratory. The housing 4 provides an air flowpath for the flow of air in a downstream direction, i.e., from the inlet6 towards the outlet 8. The term “housing” as used herein refers to anyconduit, chamber and/or enclosure, or a plurality of conduits, chambersand/or enclosures coupled to one another, providing an air flow pathwithin. Thus, the “housing” could include, e.g., ductwork of an existingheating, ventilating and air conditioning (“HVAC”) system or airhandling unit (“AHU”).

Although the housing 4 is preferably substantially rectangular cuboid,as shown in FIGS. 1 and 2, it need not be limited to any particularshape. Moreover, it may include inner curves, bends and/or othercontours, whereby the air flow path would follow such curves, bendsand/or other contours. Preferably, however, the air flow path issubstantially straight, as it is in the embodiment of the housing 4shown in FIGS. 1 and 2.

The air purifier 2 is preferably adapted to be installed into anexisting HVAC system or AHU. In an alternative embodiment, an airpurifier according to the present invention may function as astand-alone unit, i.e., one that is not part of an HVAC system or AHU.An exemplary housing 4 may be a substantially rectangular cuboid havingdimensions of approximately 11 ft. long by 4 ft. wide by 2 ft. high.Such dimensions would diffuse or spread out the air through the airpurifier 2 so as to provide sufficient resonance time for the airthrough each of the filtration media discussed infra. A skilled artisanunderstands, however, that the foregoing exemplary shape and sizeparameters are merely illustrative, and may be changed, evensubstantially, depending on the circumstances or application. Forexample, in some applications, the air purifier 2 may be about 6 ft.long.

Referring now to FIG. 3, there is shown an internal view of the airpurifier 2 along the plane defined by section line A-A of FIG. 1. InFIG. 4, there is shown an internal view of the air purifier 2 along theplane defined by section line B-B of FIG. 2.

To obtain optimal air quality, e.g., suitable for an IVF laboratory, theair that is treated by the air purifier 2 should be pre-conditioned andstable, i.e., moderate both in terms of temperature and humidity.Ideally, the air that is treated by the air purifier 2 should have atemperature of between about 68° F. and 75° F., and a humidity ofbetween about 45% and 55%. Additionally, the air flow rate through theair purifier 2 should preferably be about 250 ft./min. and below 2000CFM. This preferred flow rate is intended to provide sufficientresonance time for the air through each of the filtration mediadiscussed infra. The term “filtration” as used herein, broadly coversone or more devices that treat air, such as by trapping, removing,deactivating and/or destroying contaminants therefrom.

In order to provide an adequate air flow rate through the air purifier2, it may be helpful (although not always necessary) to include abooster fan 10 downstream from the inlet 6. The booster fan 10 may becoupled to a control system (not shown) that measures the air flow rateand triggers the booster fan 10 as needed, to maintain the desired airflow rate. In an alternative embodiment (not shown), a booster fan maynot be included, and adequate air flow rate may be provided andmaintained by other means, e.g., a blower in an HVAC system or AHU intowhich the air purifier 2 is installed.

Downstream from the inlet 6 is particulate pre-filtration 12 for thetrapping of airborne particulate. The particulate pre-filtration 12 ispreferably about 2 inches thick in one embodiment, and includes left andright pleated particulate pre-filters 14, 16. The particulatepre-filters 14, 16 trap gross particulate (e.g., dust and bugs) from theoutside air before that air reaches the other filtration media in theair purifier 2 discussed infra. Suitable filters for the particulatepre-filtration 12 are those having a Minimum Efficiency Reporting Value(“MERV”) of 5 to 13 with an Average ASHRAE Dust Spot Efficiency(Standard 52.1) of 20% to 80%. Particularly preferred filters for theparticulate pre-filtration 12 are pleated filters having a MERV of 7 to8, with an Average ASHRAE Dust Spot Efficiency (Standard 52.1) of 30% to45%.

Proper particulate pre-filter selection should be guided by the need totrap gross-particulate without unduly affecting the air flow ratethrough the air purifier 2. The particular type of particulatepre-filter(s) selected for particulate pre-filtration depends on variousfactors, including outside air quality. It is preferred that theparticulate pre-filtration 12 is located immediately upstream from theadditional filtration media discussed infra, as shown in FIGS. 3 and 4.Alternatively (or in addition), however, particulate pre-filtration maybe located further upstream, e.g., in upstream ductwork of an HVACsystem or AHU into which the air purifier 2 is installed.

Downstream from the particulate pre-filtration 12 is volatile organiccompound (“VOC”) pre-filtration 18. Once air passes through theparticulate pre-filtration 12, the air is effectively free of grossparticulate that would otherwise diminish the efficacy and useful lifeof the VOC pre-filtration 18. VOC pre-filtration ideally includesadsorption media, such as carbon, as well as oxidation media, such aspotassium permanganate (“KMnO₄”) or a photocatalytic oxidizer. Aparticularly preferred type of carbon is virgin coconut shell. In apreferred embodiment, the VOC pre-filtration 18 is a carbon and KMnO₄blend, e.g., in a 50/50 proportion. In some embodiments, the blend mayinclude additional elements, such as natural zeolite. The proportion ofthe blend may vary depending on the types and levels of VOCs present inthe source air. Ideally, the source air would be tested for VOCs, and,based on test results, a custom blend would be prepared to maximize VOCremoval in a given environment. In an alternative embodiment of the VOCpre-filtration (not shown), separate (i.e., non-blended) carbon andKMnO₄ filters are used.

The embodiment of the VOC pre-filtration 18 shown in FIGS. 3 and 4includes a total of twenty stacked filter trays 20, 22, whereby ten suchtrays 20 are on the left side of the housing 4 and ten such trays 22 aredirectly adjacent, to the right. The length of the trays, i.e., thelongitudinal distance over which the air flows, is preferably about 17inches in one embodiment, though it may be shorter or longer. Each tray20, 22 includes two blended carbon and KMnO₄ filters 24, arranged in aV-bank along a vertical plane (e.g., the plane of FIG. 3). The V-bankarrangement increases the surface area of the filters 24 over which airmust travel, thereby enhancing the effectiveness of the VOCpre-filtration 18. Once air passes through the VOC pre-filtration 18,the VOC load of the air is effectively reduced.

Downstream from the VOC pre-filtration 18 is particulate post-filtration26 for the trapping of airborne particulate, e.g., particulate generatedby the VOC pre-filtration 18 (such as carbon dusting). The particulatepost-filtration 26 includes left and right pleated particulatepost-filters 28, 30. The filters used in the particulate post-filtration26 may be identical or similar to those used in the particulatepre-filtration 12, discussed supra. While particulate post filtration 26downstream from the VOC pre-filtration 18 is preferred, it may not benecessary in all applications. For example, if the VOC pre-filtration isof a type that does not generate air-borne particulate, such as bondedcarbon, particulate post-filtration may be optional.

Downstream from the particulate post-filtration 26 is ultraviolet (“UV”)filtration 32 which destroys airborne biological contaminants and, insome embodiments, degrades chemical contaminants. Whether or notparticulate post-filtration 26 is used, the air reaching the UVfiltration 32 should be effectively free of gross particulate andcontain dramatically reduced levels of VOCs so as not to diminish theefficacy of the UV filtration 32.

The UV filtration may include one or more UV sources, although aplurality of UV sources is preferred. It is further preferred that theseUV sources are UVC sources, capable of generating UV radiation at awavelength varying from 220 nm to 288 nm. Most preferably, the UVCsources are capable of generating UV radiation at a wavelength of 260nm, however commercially available UVC sources capable of generating UVradiation at a wavelength of 254 nm are adequate. In an alternativeembodiment described in U.S. Pat. No. 5,833,740 (Brain), which isincorporated herein by reference in its entirety, the UV filtrationincludes at least one vacuum UV source, capable of generating UVradiation at a wavelength varying from 170 nm to 220 nm (preferably 185nm) and at least one UVC source, capable of generating UV radiation at awavelength varying from 220 nm to 288 nm (preferably 260 nm). In thatembodiment, the UVC source is preferably downstream from the vacuum UVsource. When operating, the vacuum UV source breaks oxygen moleculesinto mono-atomic oxygen which then reacts with chemical contaminantspresent in the air and then degrades them by successive oxidation toodorless and inoffensive byproducts. The UVC source kills biologicalcontaminants present in the air by irradiation and degrades residualozone produced by the vacuum UV source into molecular oxygen.

Particularly preferred UV filtration 32 shown in FIGS. 3 and 4 is the“UV Bio-wall” made by Sanuvox. Alternatively, the “Bio 30GX,” which isalso made by Sanuvox, is a preferred type of UV filtration. The UVfiltration 32 includes a pair of fixtures 34, 36 each of which has fiveUV lamps 38 (not all five of which are visible in the Figures). The UVlamps 38 are preferably about 60 inches long and extend longitudinallythrough the housing 4 so as to maximize exposure time of the air to UVradiation. In one embodiment, the UV lamps are UVC sources, providing UVradiation within the UVC wavelength parameters discussed supra. In analternative embodiment, described in U.S. Pat. No. 5,833,740 (Brais),each lamp 38 is dual-zoned, having an upstream vacuum UV source and adownstream UVC source. In that alternative embodiment, the upstreamvacuum UV source may, e.g., be a high intensity mercury vapor lampcapable of generating UV radiation having a wavelength in a range ofabout 170 nm to about 220 nm, and the downstream UVC source may, e.g.,be a low intensity mercury vapor lamp capable of generating radiationhaving a wavelength in a range of about 220 nm to about 288 nm. Theinterior 44 of the housing 4 encasing the UV filtration 32 is highlyreflective, with a preferable coefficient of reflection of at least 60%,so as to enhance the effectiveness of the lamps 38.

The kill rate of biological contaminants is a function of the intensityof UVC radiation produced by the UV filtration 32 and reflected by theinterior 44 of the housing 4, as well as the exposure time of suchcontaminants to the UVC radiation. Thus, the higher the intensity of theUVC radiation and the longer the exposure time of such contaminants tothe UVC radiation, the greater is the level of sterilization achieved.Depending on factors such as the desired level of sterilization, theamount of space available to house UV filtration, and costs of operatingand maintaining UV filtration, the desired total UVC output of the UVfiltration 32 may vary. In one actual embodiment, it was found that atotal UVC output ranging from about 33,464 μJ/cm² to about 90,165μJ/cm², with an average total UVC output of about 43,771 μJ/cm²,provided a desired level of sterilization, given practical constraintsof cost and space. Such total UVC output killed 100% of numerousbiological contaminants including, but not limited to smallpox, flu,tuberculosis, anthrax and H1N1 virus.

The UV filtration 32 contained within the housing 4 is likely notvisible to a user of the air purifier 2 when in use, because direct UVexposure is harmful to humans. Thus, a user cannot ascertain visually(i.e., by simply looking at the air purifier 2 itself) whether the lamps38 are operating at a given time. It cannot be assumed that the airpurifier 2 is effectively destroying air-borne biological and chemicalcontaminants, without knowing for sure that the UV filtration isoperating properly. Accordingly, it is preferred that the presentinvention include sensors and a monitor (not shown) to detect andindicate, respectively, how much time each UV lamp 38 has been in useand whether each lamp 38 is operating at a given time. The monitor mayinclude, e.g., a scrolling digital clock, which indicates the length oftime each lamp 38 has been operating. These sensors and monitor wouldindicate to a user when it is time to replace any of the lamps 38.

As a general matter, moisture within the housing 4 can foster the growthof biological contaminants. Accordingly, it is preferable to include aUVC source in the vicinity of areas in which moisture is generated orgathers. For example, upstream from the particulate pre-filtration 12may be one or more cooling coils (not shown) that help to ensure thatthe air which is treated by the air purifier 2 is moderate in terms oftemperature. Such cooling coils tend to generate moisture. It istherefore preferable to include a UVC source adjacent to such coolingcoils. Similarly, it may be appropriate to include a UVC sourceimmediately upstream from a filter/diffuser (not shown) from which theair enters into a substantially enclosed space, e.g., an IVF laboratoryor other room, after leaving the air purifier 2.

Downstream from the UV filtration 32 is VOC post-filtration 46, whichcapture, e.g., VOC by-products of the irradiation from the UV filtration32. Possible embodiments of the VOC post-filtration 46 include any ofthose discussed supra regarding the VOC pre-filtration 18. The VOCpost-filtration 46 shown in FIGS. 3 and 4 includes left and right VOCpost-filters 48, 50 that are arranged in a V-bank along a horizontalplane (e.g., the plane of FIG. 4). The VOC post-filters 48, 50, liketheir upstream counterparts, are preferably blended carbon and KMnO₄.Although VOC post-filtration 46 is preferred, in some applications, itmay not be required and may thus be omitted.

Gametes and the human embryo are highly sensitive to VOCs, even inamounts considered negligible in other applications. It is thereforeessential that the VOC filtration (both pre-filtration 18 andpost-filtration 46) operates effectively to remove VOCs from air that isfed into an environment in which IVF is being conducted. Accordingly,one or more sensors for detecting VOC levels (not shown), preferably inreal time, may be placed in an IVF laboratory and coupled to a monitor(not shown) to indicate the VOC levels in the laboratory at a giventime. With such in-room VOC detection, a user of the air purifier 2would know when it is time to replace the VOC pre-filtration 18 and postfiltration 46, and/or whether an alternative type or blend of VOCfilters would be more suitable. While in-room VOC detection isparticularly useful in an IVF laboratory, it may be helpful in anyenvironment requiring low VOC levels.

Downstream from the VOC post-filtration 46 is final particulatefiltration 52, which traps substantially all remaining particulate inthe air before the air exits the outlet 8. Final particulate filtration52 preferably includes one or more filters capable of trapping fineairborne particulate, e.g., filters having a MERV of 13 or greater withan average ASHRAE Dust Spot Efficiency (Std. 52.1) of 80% or greater.More preferably, such filters have a MERV of 16 or greater with anaverage ASHRAE Dust Spot Efficiency (Std. 52.1) of 95% or greater. Mostpreferably, such filters have a MERV of 17 or greater with an averageASHRAE Dust Spot Efficiency (Std. 52.1) of 99.97%, as do high efficiencyparticulate air (“HEPA”) filters. Alternatively, ultra low particulateair (“ULPA”) filters may be suitable. The choice of filter(s) for finalparticulate filtration should be guided by the potentially competingneeds of maintaining an optimal air flow rate and effectively removingparticulate from the air.

The final particulate filtration 52 of FIGS. 3 and 4 includes left andright 12-inch thick HEPA filters 54, 56. Preferably, magnehelic gauges(not shown) are placed both upstream and downstream from the HEPAfilters 54, 56 to measure the pressure drop across those filters. Thedegree of pressure drop will assist in the identification of the propertime in which to change the HEPA filters 54, 56, or other filters usedfor final particulate filtration.

Downstream from the final particulate filtration 52, is an atomizinghumidifier 58. The humidifier 58 may or may not be necessary, dependingon the needs of the facility in which the air purifier 2 is being used.However, if a humidifier 52 is needed, it should be placed downstreamfrom the final particulate filtration 52 so that the moisture does notadversely affect the performance of the VOC post-filters 48, 50, theHEPA filters 54, 56, or other filters used for final particulatefiltration. Humidified air can contain and support the growth ofbiological contaminants. Accordingly, if a humidifier 58 is used, anadditional UVC source (not shown) to destroy such contaminants shouldalso be included. This additional UVC source should be downstream fromthe humidifier 58, preferably at the last point in ductwork before entryinto a room served by the purified air.

An air purifier according to the present invention, such as thatdescribed in detail, supra, will produce air characterized by very highpurity, suitable for airborne contaminant-sensitive environments such asIVF laboratories or other medical environments, for example. That said,an air purifier according to the present invention is not limited to IVFor other medical applications. It may be adapted for use in anysubstantially enclosed environment, including, but not limited to,homes, residential buildings, commercial buildings, hotels, cars, buses,trains, airplanes, cruise ships, educational facilities, offices, andgovernment buildings. The invention may also have applications in, e.g.,national security, defense, or airline industries. The desired purity ofthe air may vary depending on application and environment. An airpurifier according to the present invention, such as that described indetail, supra, may be adapted accordingly to achieve a desired level ofpurity. The sequence and type of air filtration media in an air purifieraccording to the present invention provides air characterized by apurity that was unattainable with prior devices.

Accordingly, another aspect of the present invention includes purifiedair, such as that attainable using an air purifier as described herein.Ideally, such purified air would be characterized by a high level ofpurity as measured by three parameters: (a) “TVOC,” i.e., total volatileorganic compounds, measured in “ppb,” or parts per billion; (b)“Biologicals,” i.e., biological contaminants, including spores, measuredin “CFU/M³,” or colony forming units per cubic meter; and (c)“Particulate,” i.e., the number of particles per cubic foot having,e.g., nominal sizes of 0.3 μm or 0.5 μm.

TVOC measurements may be made, e.g., using GRAY WOLF SENSING SOLUTIONS,Model No. TG-502 Toxic Gas Probe with Photo Ionization Detector (“PID”)sensors utilizing a 10.6 eV lamp calibrated to Isobutylene. The lowestdetectable limit of TVOCs using the TG-502 Toxic Gas Probe is 5 ppb.

To ensure accuracy, measurements of Biologicals are preferably assessedusing two complementary methods. According to a first method ofmeasuring Biologicals, ambient air (i.e., the air being tested) is drawnover ALLERGENCO D spore traps using a high volume vacuum pump calibratedto draw 15 liters of air per minute. This is done for 10 minutes, sothat a total of 150 liters of air is drawn through the spore trapcassette. The traps are then examined by direct light microscopicobservation to determine the identification of some select types ofbiological contaminants present in terms of CFU/M³. According to asecond method of measuring Biologicals, an ANDERSON N6 sampler isutilized to obtain culturable air samples (from the ambient air beingtested) on three types of media: malt extract agar, cellulose agar andDG-18. The sampler is calibrated pre- and post-collection to draw a rateof 28.3 liters per minute for a sample time of 5 minutes. Using thissecond method of measuring Biologicals enables determination of theunique identification of any biological contaminant present in terms ofCFU/M³ due to the three different types of growth media.

The particulate measurements may be made, e.g., using a TSI AEROTRAK9306 Handheld Particle Counter. The particle counter is preferablycalibrated with NIST traceable PSL spheres using TSIs Classifier andCondensation Particle Counters, the recognized standard for particlemeasurements. The particle concentrations in the air are measured atnominal particle sizes of 0.3 μm, 0.5 μm, 1.0 μm, 3.0 μm, 5.0 μm, and10.0 μm, per cubic foot (ft³).

In a preferred embodiment, it is contemplated that purified airattainable using an air purifier as described herein, is characterizedby: (a) a TVOC content of less than 5 ppb (or below detectable limitsusing the GRAY WOLF SENSING SOLUTIONS, Model No. TG-502 Toxic Gas Probewith PID sensors described supra, or another instrument with similarmeasurement capabilities and tolerances); (b) a Biologicals content ofless than 1 CFU/M³ (or below detectable limits using the methods ofmeasuring Biologicals described supra, or other methods with similarmeasurement capabilities and tolerances); and (c) a particulate contentof from about 1,000 0.3 μm particles per ft³ of air to about 10,500 0.3μm particles per ft³ of air, or from about 600 0.5 μm particles per ft³of air to about 1,000 0.5 μm particles per ft³ of air.

Depending on the application or environment, acceptable levels of TVOCs,Biologicals and particulates may vary. For example, in one embodiment,the purified air may be characterized by: (a) a TVOC content of fromless than 5 ppb to about 500 ppb; (b) a Biologicals content of from lessthan 1 CFU/M³ to 150 CFU/M³; and (c) a particulate content of from about1,000 0.3 μm particles per ft³ of air to about 50,000 0.3 μm particlesper ft³ of air, or from about 600 0.5 μm particles per ft³ of air toabout 500,000 0.5 μm particles per ft³ of air. More preferableparticulate content is from about 1,000 0.3 μm particles per ft³ of airto about 30,000 0.3 μm particles per ft³ of air, or from about 600 0.5μm particles per ft³ of air to about 10,000 0.5 μm particles per ft³ ofair. Particularly preferred particulate content is from about 1,000 0.3μm particles per ft³ of air to about 10,500 0.3 μm particles per ft³ ofair, or from about 600 0.5 μm particles per ft³ of air to about 1,0000.5 μm particles per ft³ of air.

Another aspect of the invention includes providing purified air to anIVF laboratory to improve IVF clinical pregnancy rates and/orimplantation rates. The clinical pregnancy rate refers to the presenceof a fetal heart beat within an intrauterine sac. The implantation raterefers to the ability of a single embryo to implant within the uterusand develop a fetal heartbeat. A method of the present invention maycomprise providing purified air, such as air as characterized supra, toan IVF laboratory, performing multiple cycles of IVF in the laboratory,and achieving a clinical pregnancy rate equal to or greater than 50%and/or an implantation rate of equal to or greater than 35% based on aminimum patient population of 20 patients. In one embodiment, it iscontemplated that achievable clinical pregnancy rates would be from 50%to 70% and more preferably from 60% to 70%. In another embodiment, it iscontemplated that achievable implantation rates would be from 35% to40%.

Various aspects of the invention will be illustrated in more detail withreference to the following Examples, but it should be understood thatthe present invention is not deemed to be limited thereto.

EXAMPLES

Prior to the air purifier described herein, the national average forclinical pregnancy rates was approximately 38%. Couples often had tocomplete multiple cycles of IVF to conceive because the overall successrates were relatively low. As discussed supra, the cost of a single IVFcycle is high and multiple cycles are cost prohibitive to many.Accordingly, there has been a strong and long-felt need—essentiallysince the advent of IVF approximately 30 years ago—to significantlyimprove IVF clinical pregnancy rates in order to make IVF a more viableoption for infertility patients.

Prior to invention of the air purifier described herein, the inventorfound that IVF laboratory air quality was not conducive to thesuccessful growth of an embryo, even if extant filtration systems wereutilized. Extant air filtration systems did not deliver the air qualitynecessary to support the human embryo and thus did not noticeablyimprove IVF clinical outcomes. In addition, extant air filtrationsystems did not protect the IVF laboratory against varyingconcentrations of airborne contaminants from the outside or source air.For example, if a nearby road or roof was being tarred, the toxicchemicals released would potentially enter the source air and the IVFlaboratory and thus, impact the developing embryos.

Below are examples of how the air purifier described herein providessignificant improvements in the art, representing surprising andunexpected results and satisfaction of a long-felt and unmet need. Theexamples compare the air purifier described herein with extant airfiltration systems, including the Coda® System and Zandair System. TheCoda® System and

Zandair System have been the primary air filtration systems used in IVFlaboratories for at least the last ten years.

Example 1

An embodiment of the air purifier described herein was installed in anIVF laboratory beta site. Prior to that installation, the laboratoryused two Coda® Systems. Each Coda® System included, from an upstreamtowards a downstream direction: (1) particulate filtration; (2) carbonand KMnO₄ filtration; and (3) HEPA filtration. Prior to installation ofthe aforementioned embodiment of the air purifier, clinical pregnancyrates at the laboratory were 36.4%, which is near the national averageof about 38%. The embodiment of the air purifier described herein thatwas installed in the laboratory included, from an upstream towards adownstream direction: (1) particulate filtration (located upstream inthe air handler unit); (2) carbon and KMnO₄ filtration; (3) UVfiltration; (4) carbon and KMnO₄ filtration; and (5) HEPA filtration.After installation of the aforementioned embodiment of the air purifier,clinical pregnancy rates at the laboratory jumped to 67.4% based on apatient population of 191 patients—representing significant andsurprising results in clinical outcomes and patient care.

“Before” and “after” IVF implantation rates at the laboratory were alsomeasured. Prior to installation of the aforementioned embodiment of theair purifier, the implantation rate at the laboratory was 21% and thenational average was 26.1%. After installation of the aforementionedembodiment of the air purifier, the implantation rate at the IVFlaboratory beta site increased to 39% based on a patient population of191 patients—representing significant and surprising results in clinicaloutcomes and patient care. The significant and surprising increase inimplantation rates has allowed the program at the laboratory to returnfewer embryos per patient thus reducing the chance of multiplepregnancies (e.g., twins, triplets, etc.) and improving the overallobstetrical outcome.

In sum, these significant improvements in both clinical pregnancy ratesand implantation rates demonstrate that the aforementioned embodiment ofthe air purifier described herein achieved unexpected results relativeto the closest prior art and satisfied a long-felt and unmet need.

Example 2

The following three charts provide data from independent third partytesting of air quality in an IVF laboratory. Common to all three chartsis the following terminology: (1) “Source Air”—the air going into an IVFlaboratory prior to entering a respective filtration system; (2) “IVFLaboratory”—the ambient air within the IVF laboratory; (3) “TVOC”—totalvolatile organic compounds, measured in “ppb,” or parts per billion; (4)“Biologicals”—biological contaminants, including spores, measured in“CFU/M³,” or colony forming units per cubic meter; and (5)“Particulate”—the number of particles per cubic foot having nominalsizes of 0.3 μm and 0.5 μm. These measurements were made using measuringdevices and techniques described supra.

CHART NO. 1 IVF Laboratory Using Two (2) CODA Air Filtration SystemsSource Air IVF Laboratory TVOC 1324 ppb 1372 ppb Biologicals 469 CFU/M³1778 CFU/M³ Particulate 2,318,663 11,642 0.3 μm 0.3 μm particles per ft³particles per ft³ 1,874,789  9,421 0.5 μm 0.5 μm particles per ft³particles per ft³

Chart No. 1 compares the source air quality versus the IVF laboratoryair quality where the IVF laboratory air had been subjected to two Coda®Systems, as they are described in Example 1, supra. As Chart No. 1shows, the air in the IVF laboratory actually had higher levels of TVOCand biological contaminants (including spores) than did the source air.Only the levels of particulates dropped between the source air and theIVF laboratory air.

CHART NO. 2 IVF Laboratory Using Three (3) Zandair Filtration SystemsSource Air IVF Laboratory TVOC 594 ppb 1030 ppb Biologicals 28 CFU/M³113 CFU/M³ Particulate   380,098  5,722 0.3 μm 0.3 μm particles per ft³particles per ft³ 1,695,377 41,472 0.5 μm 0.5 μm particles per ft³particles per ft³

Chart No. 2 compares the source air quality versus the IVF laboratoryair quality where the IVF laboratory air had been subjected to threeZandair Systems. Each Zandair System included, from an upstream towardsa downstream direction: (1) carbon filtration; (2) HEPA filtration; and(3) photo-catalytic oxidation along with UV filtration. As Chart No. 2shows, the air in the IVF laboratory actually had higher levels of TVOCand biological contaminants (including spores) than did the source air.Only the levels of particulates dropped between the source air and theIVF laboratory air.

CHART NO. 3 IVF Laboratory Using a Single (1) Embodiment of Applicant'sAir Purifier Described Herein Source Air IVF Laboratory TVOC 1400 ppbLess than 5 ppb Biologicals 15,240 CFU/M³ Less than1 CFU/M³ Particulate1,063,435 5,410 0.3 μm 0.3 μm particles per ft³ particles per ft³  98,763   625 0.5 μm 0.5 μm particles per ft³ particles per ft³

Chart No. 3 compares the source air quality versus the IVF laboratoryair quality where the IVF laboratory air had been subjected to only asingle embodiment of the air purifier described herein. Theaforementioned embodiment of the air purifier included, from an upstreamtowards a downstream direction: (1) particulate filtration (locatedupstream in the air handler unit); (2) carbon/KMnO₄ filtration; (3) UVfiltration; (4) carbon/KMnO₄ filtration; and (5) HEPA filtration. Asshown in Chart No. 3, unlike the air quality results for the two Coda®Systems and the three Zandair Systems provided in Chart Nos. 1 and 2respectively, the single aforementioned embodiment of the air purifiersignificantly improved air quality with respect to all three measuredendpoints, i.e., (1) TVOC; (2) Biologicals; and (3) Particulate.

The Coda® System and Zandair System have been the primary air filtrationsystems used in IVF laboratories for at least the last ten years. Theindependent third party testing results provided in Chart Nos. 1, 2 and3 demonstrate that the air purifier described herein provided markedlysuperior air purity compared to the primary air filtration systems usedin IVF laboratories for at least the last ten years. The superior airpurity generated by the air purifier described herein is surprising.Also surprising are the significantly improved clinical pregnancy ratesand implantation rates described in Example 1, supra, resulting from thesuperior air purity generated by the air purifier described herein.

Taken together, Examples 1 and 2 demonstrate that performing IVF inambient air that has been purified to levels disclosed herein for threeparameters—TVOCs, Biologicals and Particulate—unexpectedly andsignificantly improve IVF clinical pregnancy rates and implantationrates. In addition, given that IVF has existed for approximately 30years and that the Coda® System and Zandair System have been the primaryair filtration systems used in IVF laboratories for at least the lastten years, there has been a long-felt and unmet need for an improved airpurifier for, among other things, IVF applications. The air purifierdescribed herein has satisfied that need.

Example 3

An embodiment of the air purifier described herein was installed in anIVF laboratory beta site. This embodiment included, from an upstreamtowards a downstream direction: (1) particulate filtration (locatedupstream in the air handler unit); (2) carbon and KMnO₄ filtration; (3)UV filtration; (4) carbon and KMnO₄ filtration; and (5) HEPA filtration.

A catastrophic load of VOCs was accidentally introduced into thebuilding that housed the IVF laboratory. In particular, a contractor hadpoured floor sealant on a large floor surface area in a room justadjacent to the IVF laboratory. The floor sealant comprised 10% xyleneand 40% acetone. Both xylene and acetone are highly embryotoxic. Whilestaff outside of the IVF laboratory developed nausea and intenseheadaches from the fumes, the aforementioned embodiment of the airpurifier protected the embryos and staff within the IVF laboratory. TVOCtesting before and during the accident demonstrated that despite over6000 ppb TVOCs immediately outside of the laboratory—an extremely highlevel—the TVOC levels did not change within the laboratory.

In sum, the significant and surprising results of Applicant's airpurifier, as demonstrated in Examples 1, 2 and 3, were surprising andunexpected to the inventor and would be surprising and unexpected topersons of ordinary skill in the art. Those examples also helpdemonstrate how Applicant's air purifier has satisfied a long-felt andunmet need for an improved air purifier which allows for significantlyimproved clinical pregnancy rates and implantation rates.

While the invention has been described in detail and with reference tospecific examples thereof, it will be apparent to one skilled in the artthat various changes and modifications can be made therein withoutdeparting from the spirit and scope thereof.

The invention claimed is:
 1. A method of performing in-vitrofertilization (“IVF”), the method comprising: providing purified air,wherein the purified air is characterized by: a. a TVOC content of fromless than about 5 ppb to about 500 ppb; b. a Biologicals content of fromless than about 1 CFU/M³ to 150 CFU/M³; and c. a Particulate content offrom about 1,000 0.3 μm particles per ft³ of air to about 30,000 0.3 μmparticles per ft³ of air, or from about 600 0.5 μm particles per ft³ ofair to about 10,000 0.5 μm particles per ft³ of air, and performing atleast one IVF procedure in said purified air.
 2. The method of claim 1,wherein the at least one IVF procedure comprises a plurality of IVFprocedures.
 3. The method of claim 2, wherein the plurality of IVFprocedures results in a clinical pregnancy rate of at least 50%.
 4. Themethod of claim 2, wherein the plurality of IVF procedures results in aclinical pregnancy rate of from 50% to 70%.
 5. The method of claim 2,wherein the plurality of IVF procedures results in a clinical pregnancyrate of from 50% to 65%.
 6. The method of claim 2, wherein the pluralityof IVF procedure results in a clinical pregnancy rate of from 55% to70%.
 7. The method of claim 2, wherein the plurality of IVF proceduresresults in a clinical pregnancy rate of from 55% to 65%.
 8. A method ofachieving an IVF clinical pregnancy rate of at least 50%, the methodcomprising: performing multiple IVF cycles in purified air characterizedby: a. a TVOC content of less than about 5 ppb; b. a Biologicals contentof less than about 1 CFU/M³; and c. a Particulate content from about1,000 0.3 μm particles per ft³ to about 10,500 0.3 μm particles per ft³,or from about 600 0.5 μm particles per ft³ to about 1,000 0.5 μmparticles per ft³, thereby achieving an IVF clinical pregnancy rate ofat least 50%.
 9. The method of claim 8, wherein the IVF clinicalpregnancy rate is from 50% to 70%.
 10. The method of claim 8, whereinthe IVF clinical pregnancy rate is from 50% to 65%.
 11. The method ofclaim 8, wherein the IVF clinical pregnancy rate is from 55% to 70%. 12.The method of claim 8, wherein the IVF clinical pregnancy rate is from55% to 65%.